Support for electrical transformer



1965 M. M. ARONSON 3,164,793

SUPPORT FOR ELECTRICAL TRANSFORMER Filed Feb- 5. 1959 E IN VEN TOR. Morton J4. flmnsozz United States Patent 3,164,793 SUPPORT FOR ELECTRICAL TRANSFORMER Morton M. Aronson, Bridgeville, Pa., assignor to Me- Graw-Edison Company, Milwaukee, Wis., a corporation of Delaware Filed Feb. 5, 1959, Ser. No. 791,471

1 Claim. (Cl. 336-65) This invention relates to encased electrical transformers and more particularly to means for supporting the coil and core assembly and the casing of an electrical transformer.

In conventional encased electrical transformers the coil and core assembly rests directly on the bottom casing wall, and it is necessary to reinforce the bottom plate with relatively heavy channel on angle iron base members extending the length and width of the transformer casing beneath the bottom plate so thatthe resulting base structure can support the weight of the transformer core and coil assembly and transformer oil when the transformer is lifted by jacks or slings. Such reinforcing members unduly increases the weight and over-all vertical dimension of the transformer unit. Further, such base structure does not provide a jacking surface, and it is necessary to weld horizontally extending jacking lugs to the bottom plate which increase the floor space required for the transformer unit. Also, it has heretofore been necessary to block the core and coil assembly within the casing with either blocking pins or angles to prevent movement of the core and coil assembly during shipment.

it is an object of the invention to provide improved supporting means for an electrical transformer.

It is a further object of the invention to provide improved supporting means for an electrical transformer which results in reduction in transformer height and reduction in transformer weight in comparison to prior art structures.

It is a still further object of the invention to provide improved supporting means for an electrical transformer which does not require blocking pins or angles within the transformer casing to prevent shifting of the transformer core and coil assembly during shipment.

Another object of the invention is to provide improved supporting means for an electrical transformer casing which has substantial jacking surfaces and occupies considerably less floor space than prior art transformers having separate jacking lugs.

Further objects and advantages of the invention will be apparent from the following description when considered in connection with the accompanying drawing in which:

FIG. 1 is a vertical sectional view through the preferred embodiment of the invention; and,

FIG. 2 is a partial sectional view along line 2-2 of FIG. 1.

The invention contemplates a casing having a pair of upwardly projecting step-like shelf members at the ends of the bottom wall thereof and a transformer core and coil assembly provided with lower core clamping members with inverted L-shaped cutout portions near the bottom surface and at each end thereof complementary to and interfitting with the upwardly projecting step-like shelves of the casing bottom wall to support the transformer core and coil assembly and prevent movement thereof.

Referring to the drawing, an electrical transformer casing 10 includes a pair of opposed vertical endwalls 11 connected to a pair of opposed vertical sidewalls 12. A cover .13 is preferably detachably secured to the upper end of endwalls 11 and sidewalls 12, and a bottom wall indicated generally at 14 is connected to the lower end of endwalls 11 and sidewalls 12, thereby forming a hollow casing 10 filled with an insulating liquid to the level 29.

Although the bottom Wall 14 of the casing 10 can be ice one piece, in the preferred embodiment of the invention the bottom wall 14 includes a bottom'plate 16 and a pair of step-like shelf members 15 disposed at the ends of and connected to the bottom plate 16. Each shelf member .15 includes a horizontal portion 17 spaced vertically fro:

the bottom plate 16 and a portion 18 extending upwardly from the bottom plate 16 and secured to the horizontal portion 17, preferably by welding.

An electrical transformer core and coil assembly 19 disposed within the casing 10 includes a laminated mag netic core 29 having an upper yoke 21 and a lower yoke 22 connecting three upstanding winding legs 23, 24, and 25. An electrical coil 26 is disposed on each of the winding legs 23, 24, and 25. A pair of upper core clamping channel iron members 39 are disposed on opposite sides of the upper yoke 21 and clamped thereto by bolts 31 passing through aligned holes in the channel iron members 3t? and the laminations of the upper yoke 21. Similarly a pair of lower core clamping channel iron members '33 are disposed on opposite sides of the lower yoke 22 and clamped thereto by bolts 31 passing through aligned holes in the channel members 33 and the laminations of the lower yoke 22. The lower core clamping members 33 extend horizontally beyond the core 2%, and the lower corners of the channel members 33 are preferably removed to form inverted L-shape cutout portions 35 each defined by a horizontal surface 36 and a generally vertical surface 37.

The inverted L-shape cutout portions 35 are complemtary to and interfit with the upwardly projecting step-like shelves 15 of the casing bottom wall 14 so that the weight of the transformer core and coil assembly is supported by the shelves 15. The shelves 15 also include angle iron reinforcing braces, or pulling lugs, 38 rigidly connected, preferably by welding, to the lower surface of the horizontal shelf portions 17 and to the upwardly extending shelf portions 18. Preferably the vertical portion 39 of the angle iron braces 38 is in the same plane as the lower core clamping members 33. The braces 38 have holes 41 and 42 therethrough to permit pulling the encased transformer or lifting it by a sling and also facilitate tying the transformer unit down during shipment.

The weight of the transformer core and coil assembly 19 is supported directly by the upwardly projecting steplike shelves 15. The upwardly extending portion 18 of the step-like shelves 15 is longer than the generally vertical surface 37 of the cutout portions 35, and consequently the core and coil assembly 19 is held off the bottom plate 16. Since the bottom plate 16 does not directly carry the Weight of the core and coil assembly 19, there is no need for the reinforcing base members required in prior art constructions, and further a reduction in weight and in height of the encased transformer unit is achieved. Further, the core and coil assembly 19 being supported at the extreme ends of the lower core clamping members has less tendency to rock within the casing and consequent reduction in transformer noise is achieved.

The upwardly extending portion 18 of the shelves 15 and the generally vertical surface 37 of the cutout portions 35 are spaced apart a distance less than the clearance between the ends of the lower clamping members 33 and the tank endwalls 11 in order to block the core and coil assembly 19 and prevent movement thereof against the endwalls 11, and consequently the need for separate blocking angles or pins required within the cas ing of prior art transformers to prevent shifting of the core and coil assembly during shipment is obviated.

The underside of the horizontal portions 17 of the upwardly projecting shelves 15 provide jacking surfaces for the transformer unit. The jacking lugs extending horizontally from the bottom plate of prior art transformers are thus obviated, and the floor space which the encased electrical transformer occupies is materially reduced.

The disclosed construction is more readily adaptable to gas insulated transformers in that a dome-shaped bottom plate and cover may be used since the transformer core and coil assembly does not rest on the bottom plate. Such dome-shaped casing bottom wall facilitates circulation of the gaseous dielectric and the space available between the core and such dome-shaped bottom plate can be used to house means for directing the gas coolant through the core and coils.

The invention lends itself readily to mobile substations of the type disclosed in application Serial No. 778,800 filed December 8, 19 8, now Patent No. 3,008,783 in the name of Bernard A. Barengoltz and having the same assignee as this application. In such mobile substation the transformer casing extends below the trailer frame, but the core and coil assembly is supported above the casing bottom plate in accordance with this invention and is thus protected from damage due to road impact.

Although only a single preferred embodiment of the invention has been described, many modifications and variations thereof will be apparent to those skilled in the art, and consequently it is intended in the appended claim to cover all such modifications and variations as fall Within the true spirit and scope of the invention.

What I claim is:

An electrical transformer comprising, in combination, a core and coil assembly including a magnetic core having a plurality of upstanding leg portions connected by upper and lower yoke portions, at least one of said leg portions being surrounded by an electrical coil, and a pair of elongated, longitudinally extending clamping members disposed on opposite sides of and secured to said lower yoke portion; a metallic casing surrounding said core and coil assembly and being adapted to rest upon and be pulled along a horizontal surface, said casing having a pair of horizontally spaced step-like shelf members extending transversely of said clamping members, said shelf members being integral with the end and side walls of said casing adjacent the lower end thereof, and a bottom plate connecting said shelf members and being secured to said side wall and together with said shelf members defining the bottom walls of said casing, said clamping members having at the ends adjacent the bottom thereof cutout portions complementary to and interfitting with said step-like shelf members and blocking said clamping members and said lower yoke portion secured thereto against movement relative to said casing in a direction longitudinally of said clamping members, said lower yoke portion and the lower edges of said clamping members depending below the upper surface of said shelf members and terminating in spaced relation above said bottom plate.

References Cited in the file of this patent UNITED STATES PATENTS 508,655 Thompson Nov. 14, 1893 628,957 Packard July 18, 1899 646,500 Moody Apr. 3, 1900 850,863 Woolridge Apr. 16, 1907 1,035,069 Aalbo-rg Aug. 6, 1912 1,034,934 Schaumberg Aug. 6, 1912 2,341,903 Cholewa Feb. 15, 1944 2,355,804 Hutchinson Aug. 15, 1944 2,910,663 Wilk Oct. 27, 1959 2,920,296 Neurath Jan. 5, 1960 3,007,124 Robinson Oct. 31, 1961 FOREIGN PATENTS 551,650 France Oct. 31, 1961 871,631 Germany Mar. 23, 1953 

